<?php
namespace think;

// +----------------------------------------------------------------------
// | ThinkPHP [ WE CAN DO IT JUST THINK IT ]
// +----------------------------------------------------------------------
// | Copyright (c) 2006-2014 http://thinkphp.cn All rights reserved.
// +----------------------------------------------------------------------
// | Licensed ( http://www.apache.org/licenses/LICENSE-2.0 )
// +----------------------------------------------------------------------
// | Author: liu21st <liu21st@gmail.com>
// +----------------------------------------------------------------------

/*
** 缓存管理类
*/

class Cache {
	
	/*
	** 操作句柄
	** @var string
	** @access protected
	*/
	protected $handler;
	
	/*
	** 缓存连接参数
	** @var integer
	** @access protected
	*/
	protected $options = array();
	
	/*
	** 连接缓存
	** @access public
	** @param string $type 缓存类型
	** @param array $options  配置数组
	** @return object
	*/
	public function connect($type = '', $options = array()) {
		if(empty($type)){
			$type = C('DATA_CACHE_TYPE');
		}
		
		$class = strpos($type, '\\') ? $type : 'think\\cache\\driver\\' . ucwords(strtolower($type));
		
		if(class_exists($class)){
			$cache = new $class($options);
		}else{
			E(L('_CACHE_TYPE_INVALID_') . ':' . $type);
		}
		return $cache;
	}
	
	/*
	** 取得缓存类实例
	** @static
	** @access public
	** @return mixed
	*/
	static function getInstance($type = '', $options = array()) {
		static $_instance = array();
		$guid = $type . to_guid_string($options);
		if(!isset($_instance[$guid])){
			$obj = new Cache();
			$_instance[$guid] = $obj -> connect($type, $options);
		}
		return $_instance[$guid];
	}
	
	public function __get($name) {
		return $this -> get($name);
	}
	
	public function __set($name, $value) {
		return $this -> set($name, $value);
	}
	
	public function __unset($name) {
		$this -> rm($name);
	}
	
	public function setOptions($name,$value) {
		$this -> options[$name] = $value;
	}
	
	public function getOptions($name) {
		return $this -> options[$name];
	}
	
	/*
	** 队列缓存
	** @access protected
	** @param string $key 队列名
	** @return mixed
	*/
	protected function queue($key) {
		static $_handler = array(
				'file' 		=> array('F', 'F'),
				'xcache' 	=> array('xcache_get', 'xcache_set'),
				'apc' 		=> array('apc_fetch', 'apc_store'),
			);
		$queue 	= isset($this -> options['queue']) ? $this -> options['queue'] : 'file';
		$fun 	= isset($_handler[$queue]) ? $_handler[$queue] : $_handler['file'];
		$queue_name = isset($this -> options['queue_name']) ? $this -> options['queue_name'] : 'think_queue';
		$value 	= $fun[0]($queue_name);
		
		if(!$value){
			$value = array();
		}
		
		// 进列
		if(false === array_search($key, $value)){
			array_push($value, $key);
		}
		
		if(count($value) > $this -> options['length']) {
			// 出列
			$key = array_shift($value);
			// 删除缓存
			$this -> rm($key);
			
			if(APP_DEBUG){
				// 调试模式下，记录出列次数
				N($queue_name . '_out_times', 1);
			}
		}
		
		return $fun[1]($queue_name, $value);
	}
	
	public function __call($method, $args) {
		//调用缓存类型自己的方法
		if(method_exists($this -> handler, $method)){
			return call_user_func_array(array($this -> handler, $method), $args);
		}else{
			E(__CLASS__ . ':' . $method . L('_METHOD_NOT_EXIST_'));
			return ;
		}
	}
	
}
